Engine-starting-gear limiting means



Feb- 26 1924. 1,485,085

'r. J. MARTIN ENGINE S'IAfiTING GEAR LIMITING-MEANS Filed Feb. 24. 1921JMMR /7 Stratum;

Patented Feb. 26, 1924.

TnUMAnJ. MARTIN, osarmnnrown, rnimsyrivnnia.

ENGINE-STARTIItIG-GEAR LIMITING MEANS.

Application filed February 2a, 1921] Serial No. 447,511.

To all whom it may concern:

Be it knownthat I, TRUMAN J. a citizen of the United States, residing atAllentown, in the county of Lehigh and State of Pennsylvania, haveinvented certain new and useful Improvements in EngineStarting-GearLimiting Means, of which the following is a specification.

The invention relatesto limiting means for limiting the movement of ascrew fed starting gear on the screw in connection with startingmechanisms for starting combustion engines, wherein the gear is fed intomesh with a gear carried by a fly wheel of the engine and is fed out ofmesh on said feed screw by the gear of the fly wheel after the engine isstarted. It has been found that in starting devices of this characterthat where the feed gear is limited by coming into engagement with ashoulder or a collar, that the gear is closely jammed against saidshoulder or collar by the starting motor and that when the fly wheel andits gear is rotated under control of the engine that this jamming actionwill not be broken and that the screw sleeve will be twisted off andbroken. It has also been found that where the ends of the groovesbetween the threads of the screw end in oblique angles that the feedgear will also stick and jam and cause breakage when the fly wheelstarts.

A further object is to provide radially disposed shoulders on the screwagainst which shoulders similarly shaped shoulders of the feed gearengage, said radially disposed shoulders and shoulders of the feed gearforming means of preventing jamming of the feed gear to either end ofits move ment.

A further object is to provide the feed screw and stop collar witnradially and longitudinally disposed engaging surfaces for limiting themovement of the feed gear, said surfaces forming means for preventingjamming of the feed gear on the feed screw.

A further object is to provide means for preventing sticking and jammingof the feed gear of a starting mechanism for internal combustionengines, an example of such starting mechanism being shown in Patent No.1,095,696, dated May 5, 1914..

With the above, and other objects in view the invention resides in thecombination and arrangement of parts as hereinafter set forth, shown inthe drawings, described and MARTIN,

claimed, it beingunderstood that changes in the precise embodiment ofthe invention may be made within the scope of what is claimed withoutdeparting from the spirit of the invention. 7

In the drawings Figure 1 is a top plan view of the device. Figure 2 is asectional view taken'on line 1- 1 of Figure 1.

Figure 3 is a sectional view taken on line 55 of Figure 1.

' Figure 4 is a sectional view taken on line 6-6 of Figure 1, showingholes drilled into the ends of the feed screw grooves, thereby formingsubstantially radially disposed stop shoulders for the starting gears.

Referring to the drawing, the numeral 4 designates the starting gearwhich is fed longitudinally on the threaded sleeve 5 in the usual mannerby a self starter when starting an engine, and after the engine has ibeen started, at which time the starting gear moves in the oppositedirection in the usual. manner. The threaded sleeve 5 is provided with astop sleeve 12 for limiting the forward movement of the starting gear 4,however it has been found that where the forward end13 of. the startinggear 4 comes into direct engagement with the stop collar 12 or the otherend ofthe gear 4. comes into engagement with the ends 15 of thescrewgrooves, that the starting gear becomes jammed and stuck and uponthe starting of the engine this jam is not easily broken andconsequently the'threaded sleeve is twisted in half, and the startingmechanism considerably damaged. To obviate this difficulty the stopcollar 12 is provided with a plurality of shoulders 12, which shouldershave radially andv longitudinally disposed surfaces 12*,which surfacesare engaged by similar surfaces 12 on the starting gear 4. When thestarting gear 4 moves on the sleeve 5, in the direction of the arrow 6,it will be seen that the engaging surfaces 12 of the starting gear willcome into engagement with the surfaces 12 of the stop collar and as saidsurfaces are radially disposed and also longitudinally disposed, it willbe seen that it will'be impossible for a binding action to take placeand consequently when the fly wheel starts to revolve under the power ofthe engine, the starting gear will immediatelyrotate on the threadedsleeve 5 until said starting gear is moved out of mesh with the gearteeth ofthe fly wheel. The

starting gear is prevented from sticking at the end of a reversedirection thereof in the ends 15 of the thread grooves of the threadedsleeve 5 for the reason that the ends 15 of the thread grooves arefinished ofi substantially radially as at 15, said finish being formedby boring holes in the ends 15 of the thread grooves, therebyeliminating the usual obtuse finish at the ends of the thread groovesand consequently preventing jamming of the starting gear 4 at that endof its movement.

The invention having been set forth what is claimed as new and useful isThe combination with a starting gear of an engine starting mechanism,said gear being fed forwardly and rearwardly on a feed screw and stoppedat the ends of its movement, of means for limiting the movement of thestarting gear on the feed screw, said means comprising radially disposedengaging surfaces carried by the starting gear and the feed screw, thefeed screw radial surfaces being formed by radially disposed roundapertures in the screw between the threads at the ends of said threads.

In testimony whereof I afix my signature.

TRUMAN J MARTIN.

